Means for preventing aeroplanes from taking nose dives



T. c. LUTON Oct. 22, 1929.

MEANS FOR PREVENTING AEROPLANES FROM TAKING NOSE DIVES Filed June 13, 1928 2 thereby enabling the operator to maintain the square channel 10. This collar has an in- 7 Patented Oct. 22, 1929 v I UNITED STATES PATENT OFFICE THOMAS CLEVELAND micron, on EvANsV LLE, INDIANA MEANS Eon PREVENTING ROPLAN S FROM T KING NosE nIvEs Application filed. .Tune 13, 1928, Serial No. 285,131.

The object of this invention is to provide Fig. 2, showing the pawls and the ratchet; an lmproved simple and efiicient means for and connecting a supplemental or auxiliary pro- Fig. i, is a detail view of one of the pawls. peller to the main propeller shaft of an acro In F g. 1 I have shown my device by itself, 5 plane to serve as a stabilizer which Wlll prcexceptthat the propeller is not disclosed. 55

vent a nose dive or spin or a tail spin should In Fig. 2 the nose ofan aeroplane appears engine or propeller trouble develop and to at 1,-the propeller shaft being shown at 2, afford the operator an opportunity to main said shaft having the usual clamping plates tain the equilibrium of the aeroplane to a 3 and 1. The casing or shell of my device suflicient extent tomake necessary repairs or appears at 5 and is provided with a face plate to resume flight or effect a safe landing. or base which is secured to the plate 1 by The principle of the invention is that of bolts 7.

a supplemental or auxiliary propeller and The auxiliary propeller which is carried improved means whereby the propeller may by my device appears at 8.

rotate with the main propeller during nor- The shell 5 is made in halves which are 65 mal engine operation but which will autoclamped together by bolts 9. matical'ly release from the propeller shaft The sections of the shell 5 have a square should the engine stop, fail to properly funechannel 10, and oil reservoir 11, ball races tion, or other trouble of that general nature 152 and 13, and closures or plugs 1 1-. The

develop. The said auxiliary propeller is forward part of the shell is tapered to assist adapted to run free of the engine when trouble in taking up the thrust, as will presently apdevelops and not being subject to the drag pear. or compression of the engine, it will continue Located within the shell 5 is a collar 15 to rotate for a considerable period of time, which has a square flange 16 received in the equilibrium of the aeroplane until the maternally screw threaded socket 17 which chine can be safely brought to earth or its screws on to the screw threaded end 18 of the flight resumed. propeller shaft 2. The channel 10 and the In carrying out the invention I provide flange 16 being square, the collar15 cannot an auxiliary propeller and improved attachturn within the shell and, in effect, it is solid so ing means for connecting it to the main prowith the propeller shaft 2. The collar 15 peller shaft, said attaching means having serves as a thrust bearing for the rotary relatively rotatable parts provided with antispindle 19 which carries an auxiliary profriction bearings and provided with an autopeller 8, there being rovided ball bearings 33 matic clutch, such as a pawl and ratchet, 20 between the shoulder 21 of the spindle which will enable the auxiliary propeller to 19 and the end of the collar 15, said bearings turn with the main propeller during normal taking up some of the thrust exerted by the operation or to permit automatic disconnecsupplemental propeller 8. The inner end of tion so that the auxiliary propeller may rethe spindle 19 projects within a cavity in the an volve freely should the engine slow down or collar15 and is provided with a rounded step no stop. bearing 22 between which and the step bear- In the accompanying drawings: ing 23 of the collar are located balls 24:. The Figure 1, is a side elevation of the attacharrangement described constitutes a step or ment disconnected from the main propeller, thrust hearing which, with the balls 20, takes t5 the auxiliary propeller not being shown; up the thrust exerted by the propeller 8.

Fig. 2, is a longitudinal section showing In addition to the aforesaid anti-friction my improvements connected to the main probearings, there are balls 25'1ocated in the peller shaft of an aeroplane, the main and outermost end of the shell 5 which bear on auxiliary propellers being broken away; the spindle 19-. 59; Fig. 8, is a cross section on the line 3-3, Additional means for mounting the spindle ice 19 sothat it may turn freely and easily within the shell 5 when said spindle is not coupled to the collar 15, comprise ball bearings 26 located within the race 12.

The auxiliary propeller 8 is provided with telescoping hub sections 27, 28 respectively formed integral with the clamping plates 29, 30 which engage the propeller. The hub member 28 is provided with screw threaded sockets which receive the screw threaded end 31 of spindle 19. A tapered key 32 located in a seat whose parts are formed in thehub section 27 and the spindle19, and a larger key 33 received in seats or channels in the hub sections 27 and 28, securely lock the propeller to the spindle 19 but these keys can be removed when the propeller is to be taken off. The purpose of the invention being to provide an automatic clutch or device which will lock the spindle 19'and the propeller 8 to the shaft 2 and the main propeller 34 when the engine is operating but which will enable the propeller 8 to revolve freely when the engine is stopped and in order that the propeller may not be subject to retardation by the compression of the engine, I provide means for effecting this purpose. As shown, such means comprise a pawl and ratchet mechanism but it is to be understood that any suitable means may be employed.

7 As shown, the collar 15 is provided with pockets 35 (Fig. 3) and there are pawls 36 which are roekably seated in one end of each pocket, said pawls being adapted to be received in the pockets to free the spindle 19 when the shaft 2 slows down or stops. The spindle 19 is provided with ratchet teeth 37 which are adapted to be engaged by the pawls 36 during normal operation. When the engine slows down or stops, the continued rotation of the spindle 19 and propeller 8 causes the pawls to be forced into the pockets 35, the propeller 8 then revolving freely and not being subject to the drag of the engine.

The pawls 36 may be gravity operated or they may be provided with springs 38 secured at 39, as shown, said springs tending to urge the pawls toward the ratchet 37.

To prevent vibration ofthe shell 5 in relation to the collar 15, I provide screws lO'which are entered through the shell 5 and having their tips engaged with the collar 15.

In brief, the engine may be started by turning the propeller 8 by hand, the pawls 36 then engaging the ratchet 37. hen the engine starts, and while it is normally operating, the auxiliary propeller 8, the spindle 19, the collar 15, and the shell 5 turn as a unit with the propeller shaft 2 and the propeller 34. If, however, the engine should stop or slow down, the propeller 8 will freely revolve,

the ratchet 37 pressing the pawls 36 back into theirpockets. The continued rotation of the supplemental propeller gives stability to the aeroplane so that the operator may maintain its equilibrium until he makes a safe landing or until the engine again functions properly to couple the collar 15 to the spindle 19, thus nose dives and tail spins are overcome and the operation of the aeroplane is rendered much safer.

lVhat I claim is:

1. A safety attachment for aeroplane propellers, comprising a shell adapted to be attached to the main propeller shaft, a main propeller, a spindle mounted to turn within said shell, a supplemental propeller attached to said spindle, and a releasable clutch for connecting the spindle to the main propeller shaft, said clutch enabling the supplemental propeller to rotate with the main propeller and to continue to rotate independently thereof after the main propeller slows down or steps.

2. A safety attachment for aeroplane propellers, comprising a shell adapted to be attached to the main propeller shaft, a main propeller, a spindle mounted to turn within said shell, a supplemental propeller attached to said spindle, a thrust bearing connected to said shell, said spindle being seated on said thrust bearing, and an automatically releasable clutch for connecting the spindle to the main propeller shaft, said clutch enabling the supplemental propeller to rotate with the main propeller and to continue to rotate independently thereof after the main propeller slows down or stops.

In testimony whereof I aflix my signature.

THOMAS CLEVELAND LUTON. 

